Telephone system



Nov. 9, 1926. 1 C. B. FOWLER TELEPHONE SYSTEMl Filed Nov. 30 1923 2 Sheets-Sheet 1 Novi 9 ,'1926.

c. B.`FowLER TELEPHONE SYSTEM 2 Sheefs-Sheet 2k Filed Nov. 50 1923 Nov. 9, 1926.

g .iseaii CLARENCE E. ,ECWLER 0E NEW velan,` N. Y., `lAssIerNoRfro WESTERN ELECTRIC COM- PANY, INCORPORATED, CE NEW YoaK, .N. Y., A CoRPoRAfrroNoEyNEW YORK.

TELEPHONE -sYs'TE'aL Application sied November 3o, i923. serial No. 677,828;

This invention relates to telephone systems and more particularly to connecting circuits employed in extending connections from subscribers lines terminating in a plurality ot connecting terminals. n

Among the objects of this invention 1s vto simplify and improve the connecting cir- Y cuits of the above mentioned type.

A feature ot 'this invention resides in the provision of a relay in a connecting circuit which responds to theinsertion of the answering plug oi the connecting circuit into the jack of a calling line forconnecting the operators telephone equipment to the connecting circuit, and vfor, operatively asso` ciating ringing equipment, Common to al pluralityot connecting circuits, to the calling end ot the connecti-ngcircuit employed.

Another feature oit the-invention resides in the provisionot a relay in a connecting circuit responsive to the connection of the answering plug with a calling .line to cause `the connection oit the operatorsl testing' equipment and the common ringing equip-v inent with the connecting circuit, and re-i` sponsi've to the disconnection of the calling party to remove the Control oi' `the supervisory signaling apparatus of the connecting circuit from the calling party.

A still further feature relates to. a relay in a connecting circuit which responds to* the actuation of a key common to'a plurality ot connecting circuits for causing the application of ringing current t-o the calling end ot the connecting circuit, and responds to the actuation of another key coinniontothe connecting circuits to prevent the appli- V"cation of ringing current to the calling end ofthe connecting circuit.V

It is believed vthe invention'vwill best understood froml the 'following detailed 'description made with reference to the accom-V panying drawings.

ln the drawings zV `Fig. l shows a calling line A terminating at a Ycentral exchange in a plurality of answering jacks and'in a Amultiple jack, a' four party line D, having similar terminals at the central eXchange,and the cord Circuit C employed in extending a connection between the lines A and D.

Fig. 2 shows an operators telephone set and testing equipment O, together with the ringing equipment necessary in signaling vthe different parties on the line D (Fig. l)c

In the following description the subscriber on theline A Willbe considered the f calling subscriber Iand any one lof the partieson the line D, thel calledsubscriber. yThe signaling oit each party on the line D', hoW- ever, Vwillfbe 'described'infdetail..

Upon initiating a call,'the subscriber vat i -ctation A 'removes therec'eiverjsfrornA the svvitchhoolr and. establishesfan .obvious circuit for the line relay 3, which thereupon operates. "Relay 3 Vin operating, completes a circuit extendingy from', grounded battery, f through the fiilaments of 'lamps 8 and9,

which lamps 'are loeatedjinfront of ldifferent Voperators at `the central offiice, any Aone oit operator at the position atrwhich lamp .Sie

located is tree to liandlethe incoming call.k

This operator, therefore, insertsfplug 11 associated withl the cord'circuit 'C into jack l2 located at her position and @associated with the calling subscribersline.

VUpon the insertion of plug 11 into jack l2,l a starting relay 20 common to the 'link circuits oft the operators position, operates over a circuit from` ground, 'through the winding of rcut-ott relayl lf, sleeve contacts,

.jack l2 and plug' 11,3Winding andk Contact 64 o'trelay la, contacts (35 of relay 52, conf ,ductor 1.75, contacts of relay 31contacts 67 otrelay 82, winding of relayQO, contacts 58 of relay 35`to groundedbattery'overthe contacts V 69 of relay Relays .4 v'and v14 are marginal and do not receive' suflicient .current at this time kto operate.A Relay? 20 in operating, causes" theV operation vofv relay 32.V Relay 32"vr in attracting its inner left hand armature,` O'Piens at its; contacts shunt 'path normally. connected around thev polarized relays 30 and 40, connects ground between resistance 19 and-relay QOand at iti; outer left' handvv armature connects`v .grounded battery throughresistance.,18, be-

tweenV relay140*'andfresistaiice'lti With re' .69 roi, vrelay. to

'lay' 32 .operated fand with' ground andr iio Since the line has been assuined to be Vtree, current will now flow through relays 30 and 40 over conductor 75 in a directionA such as to operate relay 30. Relay 40 does not opera-te at this tiine as the current flow through its Winding is notin the proper direction. The current path for relay 30 inay be traced troni ground through the Winding of cut-oil relay 4, sleeve contacts ot jack 12 and plug 11, Winding` and contacts 64'ofrelay 14, contacts 65 of relay 52, conductor 175, vcontacts 66 of relay 31, windings of relays 30 y and 40, contacts 73 'of relay 32, and thence through one arni of the potentiometer circuit, including resistance 18 to @rounded battery.A It will be noted that current also ilovvs at this time through resistance 18 and i Vresistance 19 r(forming the other ari'n ot the potentiometer circuit) to ground, but thisL u vcurrent is ineiectual Relay 30lin operating, completes a circuit for relay 31, over a path troni grounded bat- V'tery,` through the armature and contact of relay 30, lett hand ivinding'ot relay 3l tov -ground on the `right hand contacts ol relay 32. Relay 31 thereupon operates and locksl .over a path extending iroiii grounded battery, left hand alternate contacts and 'Winding of relay 31 to ground at the right hand contacts of relay 32.

in operating, also opens at its contacts 66 the circuit ior relay,30,\Where'upon this re-v lay releases.

In attracting its right-hand' armature relay 31 connects its right hand Windingvand resistance 17 in multiple to conductor 175. This circuit being established beforethe release of relay 32, relay 31 'remains operated after the release of relay The connection of .grounded battery through the right Winding of relay 31 and Lresistance 17 in parallel, increases the current flow over the conductor 175 suliicieiitly to permit the operation oi''rnaarginal relays 14 andV 4.

i Relay 14 in'operating locks over a path. extendingv from ground, through the Winding of cut-oilg relay v4, sleeve contacts oi jack 12 Y and plug 11,.Winding and Contacts 61 of relay 14, to groundedbattery at the contacts 1790i relay 52, At its armatures 33 and 34,

relay 14 connects grounded battery and ,ground to the ring and tip of the answering .end of the cord circuit C through the Winding of supervisory relay 13, which relay thereupon operates over the closed subscrib- Vers line loop. In attracting its arniature,

relay 13 connects battery to a contact of relay 52 or future use. Relay22 now operates 1n a circuit extendingfroin grounded battery, armature 33 and front contacts of, relay 14, conductor 37, vvindingof relay 22,

. ina liter be traced.

yline is idle, she. iiisertsvplug 47 into jack `48, of the called line. f

Relay 31 i-n operating, opens atits contacts 69 the energizing circuit tor relay 29, whereupon relay 2O releases,l Awhich in turn releasesvrelay 32. Relay 31 "now locked under the control ol' relays Aback contact and right hand arinature of relay 85, conductor 38 to ground at the contact 39 oi key 41. y

Cut oft' relay 4 operating in the circuit hereinbet'ore traced, removes theline relay 3 troni the calling line, whereupon this relay releases and opens the circuit for lainps 3 and 9, which thereupon are extinguished.

Relay 22 in operating, as described, connects at its arinatures 42 and 43, the listening leads troni the operator-s telephone set, to the cord circuit C. At its armature 44, relay 2 2 prepares a circuit for niarginavl relay 60 and Yfor relay 97 in the operators position equipment. At its arniaturesr45 and 46, relay 22 prepares circuits Whichivill here- The operators headset being connected across the talking VVco iductors of the cord circuit, the operator ascertainsv the nature ot' the desired connection. -Upon learning that a party on the line D is desired, the operator nialres the Ausual busy testand it the desired ',.The .insertion ot plug 47 into jack 43 `causes relayr52 tooperate over an obvious ysleyre,circuit includingthe Winding ojt cut- V,ott relay 56. Atits arniature172, relay 52 causes vcalling supervisory lanip 49to Vbe illuminated over an obvious circuit, and also connects battery to the back Contact kot the trippingrelay 84 and to the Winding Vof relay 35. The battery at the back contact oi'" relay 34 flows through the Winding oi niarginal relay 60, Jfront contact vand'armature 44 01"' .relay 22, conductor 54 yto ground vthrough the winding ot relay 97. Relay 69 libri does not receive suiicient current at this tinie and The inalc-lietore-brealt contacts ot relayl :i2 Vand the slonv releasingfch tics oi r lay 14 enable this battery rans'lfer to be ina=` e Without causing'relay 14- Y lease its armatures. At' its contacts relavf52 also connects battery to the vvindi Dit' relay 22.

' i the calling subscriber asks tor a connection With party lll, the operator actuates lrey lV for an instant to cause the desired party to be rsigifialed automatically.

The actuation o't key 3V euses relay 75 to be operated. ,ff-at .is contacts relay 75 grepares iiliepeg-eoiint relays 92 and 93 `tor actuation. lt inay be stated here that the peg-count circuit is en'iployed only at certain `relay 23 to operate to disconnect the op interyals when ra check on the number of calls handled by the operator is desired, and when such a check is to be made, key 155 is actuated, so that upon the actuation of any ot the ringing keys, or the trunk key T, the circuit tor relays 92 and 93 Will be completed, and the peg-count device actuated. At its contacts 57, relay 7 'connects ground to the lead 54 thereby shunting relay 97 to eX- tinguish the pilot signal 98l and to cause marginal relay 60 to receive sutlicient current tooperate. At its contacts 58, relay 75 causes erators telephone set from the cord circuit.

Relay 60 in attracting its armature 24, locks under the control of both relays 84 and 52. At its armatures 25 and 26, it removes the vshort circuit normally around the ringbacl-tone condensers 88 and 89. In attracting its armature 25, relay 60 connects the ground on the outer left hand armature ot relay 79 to the tip side ot the calling end ot the cord circuit C. At its armature, 27, relay 69 completes the energizing circuit Jfor relay 85, which circuit was initiated by the operation ot relay F Then relay 85 operates, a4 circuit tor aspecial code ot' ringing current is established which may be traced trom the ringing current source'190 Fig. 2) through the interrupter 28, conductor 29, contacts 62 of relay 63, Winding of tripping relay 84, iront contact and left hand armature ot' relay 85, outer right hand armature and'bach contact or" relay 70, front contact and armature 26 of relay 6 0, ringlcontacts of plug 47 and jack 48, through the bells at the subscribers station l to ground, The condensers 88 and 89 serve to complete a path back to the callinosubscribers line. thereby` enabling the subscriber to hear the ringing signal. d

Should the party R be 'desired by the calling subscriber, the operator Would momentarily actua'te key R', -Whereupon relay 74 operates. At its contacts 177, relay 74 causes relay to operate in a circuit extending `from grounded battery over the armature 172 and firont contact ot' relay 52, back contact andarn'iature of tripping relay 84, Windingof relay 63, conductor 71, t'ront contact and armature 46 of relay'22, conducto-r 77 to ground on the contacts 177 of relay 74. At; its contacts 78, relay 74 causes relay 75 tooperate causing the closure of the pegcount. circuit,v the shu-'nting of relay 97, the vextinguislnnent of pilot'lamp 98 fand the operation ot' relays 60 and 23 as liereinbeiore described.

Relay inxattracting its armature 79, 4locks up under the control ol' relays 84 and At -itsarmature 82, relay 63 prepares a circuit for relay 83, and at its contactf86, )reparos the connection ot lead 87 tothe ring side ci the cord which .Will be completed when relay 83 operates.

At the proper interval,.battery from the ringing equipment .will be connected to the lead 99 through interrupter 91, whereupon relay 83 operates in a circuit extending `from grounded battery on the lead 90,' normal make-betore-break'contacts of relay 83 Winding -oiu relay 83, armature 82 and front contact ot relay 63 to ground. Relay 83 operates and in attracting its outer armature, locks up'independently ot' lead 90.` At its inner armature, relay 83 causes a special current code to be connected to the ring side of the cord. This path maybe traced from the ringing current source 190 (Fig. 2) over thev interrupter 94, conductor 87, front contact and inner armature of relay 83, contacts 86 of relay 63, Winding oi relay 84, lett' hand armature and front contact ot relay 85, conductor 67, outer right hand armature and back contact oi' relay 70, front contact and armature 26 of relay 60, ring contacts of plug 47 and jack 48 and thence through'the bells at'the subscribers station R to ground.

it the operator -receives a request for party J, she momentarily actuates the cory responding-'key J, whereupon erelay 73 operates to cause the functioning of the pegcount equipment, to shunt out relay 97, eX- tinguish the pilot lampl 98 and operate relays 23 and 60, in the same manner as described 'in connection with the actuation ot' key R. At its contacts 96, Arelay 73 connects groundwto the conductor 99y causing relay 70 to operate in a. circuit extending from grounded battery, over the right hand armature and frontcontact of relay`52, back contact and armature of relay 84, right hand Winding of relay 70, front contact and arniatu're 45 et `relay 22, conductor 99 to ground on the contacts 96 of relay 73.

Relay 70 at its outer lett hand armature connects ground vtothe ring'sidevof the lcord C by Way 'of its frontv Contact, and the front contact and armature 26 of relay'60. At its inner left hand armature, relay i70v locks. At its outer right handarmat-ure, relay 70 prepares a circuit for `transmitting ringing currentl over the tip side of the cord, and` at its inner right Ahand'armature, itestablishes an energizing circuit orrelay 85 to grounded battery on the iront contact and arma-` ture 172 of relay 52. After an interval, slow f operating relay 85 operates and locks to ground on the normal Contact 39 of key 41. At its lett hand armature, relay 85 completesthe circuit to the tip conductor ot the cord Which circuit was initiated by relay 70 at its outer right hand armature. Y

Ringing current now passes through inten.

rupter 28 over conductor 29, contact 6 2 of i2 relay 63, Winding of tripping relay 84, front contact and inner left hand armature of relay 85, conductor'67, outer right hand arma'-r yture yand front contact of relay' 70, yfront contactand armature 25 of 'relay 60,1tip conto operate.

tacts of plug 47 and jack 48 through the bells at the subscribers station J to ground.

To signal party h the operator momentarily actuates key M causing relay 72 y Relay 72 in operating, causes both relays 73 and 74 tooperate, which in turn causes relay 75 to operate. Relay 75 at its contacts 59 causes the peg-count equipment to function while at its contacts 57, it shunts out relay 97 causing the eX- tinguishment of the ringing pilot lamp 98, and the operation 'of relay 60.` At its contacts 58, relay 75 operates relay 23 to disconnect the operators telephone set from the cord circuit. Relay 74 at its contact 77 causes relay 63 to operate as described in connection with the actuation of key R. Relay 63 performs the same functions as previously described, namely locks itself un- "i der control of relays 84 and 52 and prepares relay 83 for operation.

Relay 7 3 at its contacts 96 causes relay 7 0 to operate and lock under the control of relays 84 and 52, to connect ground to the ring conductor of the cord by way of the front contact and armat-ure 26 of relay 6() and to prepare the tip side of the cord for the transmission of signaling current thereover.

' At the proper interval, battery will be connected to conductor 90 by way of intere rupter 91, whereupon relay 83 operates to ground on the front contact and armature 82 of relay 63. Relay 83 in operating, locks under control of relay 63.

The circuitfor ringing current may -now be traced 'from the ringing current source 190 through interrupter 94, conductor 87, front contact and inner armature of relay 83, contacts 86 of relay 63, winding of relay 84, left handarmature and front contact of relay 85, outer right hand armature and ront Contact of relay 70, front contact and armature 25 of relay 60, tip contacts of plug 47 and jack 48 through the bellsat the subscribers station .M to ground.

Should the operator neglect to depress the ringing key such as M, J, R Vor lV for a suiiici-ent length of time or to a suihcient ertent, the ringing pilot lamp 98 will vremain lighted: Upon noting 'the continued illumi-v nation of lamp. 98, the operator will vknow that the ringing equipmenthas not functioned and she will again actuate the ringing key.

1n each of the preceding yringing operations relay in operating, opened the circuitktor relay 22 which in releasing disconnected the operators telephone set and the common ringing leads 54, 48 and'99` from the cord circuit.

Although ringing current passes through the winding of relay 84, in eachot the above ringing operations, this relay being mar-v ginal, does not operate on these occasions.

tripping relay 84 is effected in the following manner. When the called subscriber such as the subscriber at station J, removes the receiver from thev switchhook, the condenser 165 associated with the sub-station equipment is short-circuited by the switchhook contacts,'thereby reducing the resistance of the ringing current circuit to such an extent as to permit ymarginal relay 84 to operate.

The ground connected to the tip or ring conductors of the coid circuit by the outer left hand armature of relay 70 depending on whether or not this relay is operated, serves as a return path for the ringing current when the subscriber removes thereceiver -from the switchhook.

The release of relay (S3-as above mentioned, causes relay 83 to release if operated. Relay 60 in restoring, as above mentioned, again shunts the ring-back-tone condensers 88 and 89 and renders the tip and ring conductors ot the calling end of the cord circuit C continuous. vUpon the release of armatures 26 and 24 ofrelay 60, rthe calling supervisory relay 100 operates from battery, associated with the repeating coil 15, over the closed subscribers line loop. Relay 10() in operating, causes lamp 49 to be extinguished. Should the called subscriber at any time desire to flash, he may do so by actuating his receiver switchhook, thereby interrupting the closed line loop, and causing relay 100 to be intermittently deenergized, whereupon the lamp 49 flashes.

At the termination of the conversation,

the called subscriber in restoring'his receiver, l i.

will cause lamp 49 to glow steadily, which serves as a disconnect signal to the operator. Y

lNhen the calling subscriber at station A replaces his receiver on the switchhook, the circuit for supervisory relay 13 is opened, whereupon this relay releases. Relay 13 in retracting its armature, Vopens the locking circuit for relay 14.. This relay thereupon restores its armatures. Relay 14 inretract ing its armature 33, causes theV answering supervisory lamp 55 to be illuminated in a circuit extending from grounded battery, ar-` mature 33 and back contact of relay 14, ila' Y ment of lamp 55, iront contact and right hand armature ot relay 85, conductor 38, to ground on the contacts 39v of key 41. In retracting its armatures 33 and 34, relay 14 disconnects ground and battery. from the answering end of the cord circuit. With supervisory relay-13 deenergized, the circuit for cut-ott relay 4 is also opened, whereupon this relay releases and in retracting its armatures, reconnect-s the line relay 3 to the calling line. Should the calling party desire tion of plug 11 with jack 12 for operation have been released.

Upon the removal of plug 47 from jack 48, relays 52.and 56 are deenergized. Relay 56 in retracting itsv armatures, reconnects the line relay 53 to the Called line D. Relay 52 in retracting its armature v172,v disconnects battery from the circuit including the filament of calling supervisory lamp 49, whereupon this lanip'is extinguished. Re-

lay 52 also disconnects battery from the winding of relay 85, whereupon this `relay releases, and opens the circuit'for calling supervisory Vlamp relay 55, whei'eupon this lamp is extinguished. The coi'd circuit equipment is now in normal condition.

On a connection over a trunk circuit (not shown) to which `ringing current is not to be applied the operator will depress the trunk key T after having inserted the plug 47 into the jack of the trunk (not shown) it now being assumed that the answering plug 11 has already been inserted into the jack, such as 12, of a calling line. The trunk circuit comprises at its outgoing end simply a tip and ring conductor connected to a jack such as 48 and a sleeve conductor having a suitable resistance therein. Such an arrangement is so old and well known that it is not deemed necessary to show it. Upon the insertion of plugs 11 and 47 into jack 12 and the. jack ot an outgoing trunk circuit respectively, the cord circuit equipment associated with the answering end, functions in the same. manner as hereinbefore described. The operator then actuates the trunk key T causing relay 76 to operate. Relay 76 at its contacts 110, causes the peg-count equipment to function as in the previous operations. At is contacts 111, relay 76 connects ground to the conductor 99 which causes relay 70 to operatek in a circuit extending from grounded battery, armature 172, and front contact Voitrelay 52, back contact and armature of relay 84, both windings of relay 70, front contact and armature 45 of relay 22, conductor 99 to ground on the contacts 111 of relay 76. Relay operates in this circuit and locks thereby removing its control from relay 22.

, Unless relay 60 is operated, relay 70 performs no ringing function. At its right hand armature, relay 70 causes relay 85 to operate in an obvious circuit. f Relay 85 locks under the control of key 41 and' opens' the circuit for relay 22 which thereupon releases, causing the disconnection o 'f the commonringing and listening leads'trom the cord circuit.

It is. therefore apparent 'that by the particular arrangement shown, applicant has devised a system wherein an operator performs the saine operations on both types of connections, one requiring ringingv by the operator and the'other which requires no ringing by the Operator.

Should the calling party'inake aA request for another partyon the same line, theoperator will instruct rhim to replacehis receiver on the switchhook. vWhen the operator,

hears-the disconnect click, caused bythe placing yof the receiver on the switchhook, she removes the plug 11 from the answering jack 12 and'replaces it withk the calling plug an obvioussleeve circuit causing relay 22 to operate to connect the common 'ringing initiate the ringing signal. .A Vlien the ring. ing starts, the relay 22 releases as hereinbefore described to remove the common ringing and listening leads Jfrom the cord. Should the calling party come back on the connection too soon, the tripping relay 84 1s operated ashereinbetore described totrip the ringing current.

A If for any reason an operator, after having inserted her answering .plug into the jack of a calling line. shouldk desire to re`- lease lier talking and testing equipment and the 'common' ringing equipmentV without plugging into the called line she maydoso by depressing key 41 thereby opening the energizing circuit for relay 22 which releases toI perform the desired operations.-

By'this arrangement it is unnecessary Vfor the operator lto release the calling subscribers line on'sucli an occasion.

What is claimed is: v 1. In aftelephone system, a calling line, a called line, a plurality yof connecting circuits, an operators telephone set common to said connecting circuits, ringing control equipment common lto said connecting cirof said connecting `circuit with said called.

line, ,and the actuation of said ringing control equipment, to cause said telephone set;

and said ring-ing control equipment to be disconnected from said connecting circuit.

2. In a telephone system, a calling line, a

y The operator then actuatesthc` key corresponding to the party desired to A. -85 Upon this operation, relay 52 operates in iso called line, a plurality of connecting circuits having answering and calling ends, an operators telephone set common to said connecting circuits, ringing control equipment common to said connecting circuits, means responsive to the connection of the answering end of one ot said connecting circuits with said calling line for connecting said ytelephone set to said connecting circuit and for operatively associating said ringing control equipment with the calling end thereof and means responsive to the connection of the calling end of said connecting circuit with said called line, and the-actuation of said ringing control equipment, to cause said telephone set and said ringing control equipment to he disconnected trom said connecting circuit.

3. In a telephone system, a calling line, a plurality of connecting circuits, an operators set common to said connecting circuits, ringing control equipment common to said connecting circuits, a relay for each of said connecting circuits operated in response to the connection of one ot said connecting circuits with said calling line, means responsive to the operation of said relay for connecting said telephone set with said connecting circuit and for operatively associating said ringing control equipment therewith and means responsive to the actuation of said ringing control equipment tor cause said telephone set and said ringing control equipment to he disconnected from said connecting circuit.

4. In a telephone system, a calling line, a called line, a plurality of connecting circuits, an operators telephone set common to said connecting circuits, ringing control equipment common to said connecting circuits, a relay ior each oi' said connecting circuits operated in response to the connection of one end of one of said connecting circuits with said calling line, a second relay controlled `loy said rst relay for connecting said telephone set with said connecting circuit and for operatively associating said ringing controlv equipment therewith and means jointly responsive to theconnection of the other end of said connecting cir- Ycuit with said called line, and the actuation of said ringing control equipment, to cause said second relay to disconnect said ringing control equipment from said connecting circuit.

In a telephone system, a calling line, a called line, a plurality ot' connecting airciiits having answering and calling ends, an operator-s telephone set common to said connecting circuits` ringing control equipment common to said connecting circuits, a relay foreach of said connecting circuits responsive to the connection of the answering end of one of said connecting circuits with said calling line for connecting said telephone set to said connecting circuitand for operatively associating said ringing control equipment with the calling end thereof and means jointly responsive to the connection of the calling end of said connecting circuit to said called line and the actuation of said ringing control equipment to cause said telephone set and said ringing control equipment to be disconnected from said connecting circuit.

6. In a telephone system, a calling line,

ya called line, a plurality of connecting circuits having answering and calling ends, an operators set common to said connecting circuits, ringing control equipment common to said connecting circuits, a relay for each of said connecting circuits operated in response to the connection of the answering end of one of said connecting circuits with said calling line, and a second relay responsive to the operation oit said lirst relay for connecting said telephone set with said connecting circuit and for operatively associating said ringing control equipment with the calling end thereof and rmeans jointly responsive to the connection oi'said calling end oi? said connecting circuit with said called line and the actuation of said ringing control equipment to cause the disconnection of said telephone set and said ringing control equipment from said connecting circuit.

7. In a telephone system, a calling line, a called line, a plurality of connecting cir` cuits, an operators telephone set common to said connecting circuits, ringing control equipment common to said connecting circuits, a sleeve relay for each of said connecting circuits, operated in response to the connection of one end oi' one of said connecting circuits with said calling line, and means responsive to the operation of said sleeve relay for connectingV said telephone set with said connecting circuit and for operatively associating said ringing control equipment therewith and means jointly responsive to the connection of tlieotlier end of said conloo necting circuit with said called line and the actuation of said ringing control equipment to cause the disconnection oi said telephone set and said ringing control equipment from said connecting circuit. Y

8. .ln a telephone system, a calling line, a called line, a plurality of connecting circuits,v an operators telephone set common to said connecting circuits, ringing control equipment common to said connecting circuits, a sleeve relay for each of said connecting circuits operated in response to the connection ot' one end of one of said connecting circuits with said calling line, and` a second relay controlled by said sleeve relay for connecting said telephone set with said connecting circuit and for operatively associating said ringingcontrol equipment therewith and means jointly responsive to a called line, a connectingcircuit intercon-l necting said lines and having calling and answering ends, a: sleeve relay associated with the answeringend of said connecting..

circuit operated in response to the connection of the answering .end ci said connecting circuit with'said calling line, a supervisory relay operated in response to the operation of said sleeve relay, a locking circuit ior said `sleeve relay controlledv by said supervisory relay and established iii response to the connection ot the calling end of said connecting circuit with said called line, a supervisory circuit controlled by said sleeve relay and completed in response to the connection of the calling endvoi said connecting circuit with said ca lled line, a supervisory signal and circuit connections whereby in response to the restoration of the receiver on the calling line said supervisory signal is actuated, said supervisory relay' is removed from said connecting circuit and the locking circuit for said sleeve relay opened.

10. In a telephone system, a calling and a called line, an operators link circuit having manual connection terminals for connecting with said lines, a supervisory relay in said link circuit, a sleeve relay associated with each of .the manual connection terminals of said link circuit, one of said sleeve relays controlled over one of the connected lines for operatively disassociating the station of said line romsaid link, and a holding circuit for said one sleeve relay including contacts of each of the sleeve relays and said supervisory relay.

11. In a telephone systema calling line, a called line, a connecting circuit interconnecting said lines, a. supervisory signal, a supervisory relay normally disconnected from said connecting circuit, a second relay responsive to the connection of said connecting circuit with said calling line for connecting said supervisory relay to said connecting circuit whereby said supervisory relay operates to effect a locking circuit for said second relay and responsive to a disconnection by the subscriber on said calling line for actuating said signaling device and removing said supervisory relay from said connecting circuit. p

12. In a telephone system, a calling subscribers station, a called subscribers station, a cord circuit interconnecting said stations, a relay associated with said cord circuit and operated in response to the connection of said cord circuit with said callsaid relay, a locking circuit `for said relay` controlled from said calling subscribers,y station, and means controlled at said call-v` ing stati-on for interrupting said locking circuit whereupon said signaling device is I actuated and removed from further control of the calling station.

13. In a telephone system, a calling subscribers line, a connecting circuit having ingistation, a signaling devicecontrolled byy answering and calling ends, ringing equip- Vment including a plurality of keys, a ringing current source, means responsiveto the connection of the answering end of lsaid connecting circuit with said calling` llinefor associating said ringing equipmentwith Athe 'calling end of said connecting circuit, and a plurality of relays in saidv connecting circuit operated in response to the actuation orp one of said keys for transmitting afringing current from said sourceover the calling end of said connecting circuit, one of said relays vbeing also repsonsive to tlie actuation of another ot said` keys for preventing the transmission of ringing "cui-rent.

14. In a telephone system, a calling sub-v scribers line, va connecting circuit having answering and calling ends, ringing ,equip-- ment including a plurality of keys for said connecting circuit, a ringing current source, means responsive to the connection of the answering end of said connecting circuit 'with said calling line for associating said ringing equipment with the calling end of said connecting circuit, and means including a relay in said connecting circuit responsive to the actuation of one of said keys tor transmitting ringing current from saidA source over the calling end of said connecting circuit, said relay being also responsive to the actuation of another of said keys to prevent the transmission of ringing current.

15. In a telephone system, a calling line, connecting circuits, an operators testing equipment, ringing equipment common to a plurality of said connecting circuits, supervisory signaling apparatus for: said 'connecting'circuits, a relay in each of said connecting circuits responsive to the connection of one thereof with said calling line to connect said testing equipment and vsaid ringing equipment to the connecting circuit employed, and means controlled by said relay when the subscriber and said calling line disconnects, for removing the control of said supervisory apparatus from the calling line.

16. In a telephone system, a calling line, a called line, a plurality of connecting circuitsl having answering and calling plugs, a relay operated in response to a connection of the answering plug of said connecting circuits with said calling line, a plurality of ringing keys common to said plurality of connecting circuits, an operators telephone set, said keys and said telephone set being associated with one of said connecting circuits when said relay is operated, and means responsive to the connection of the calling plug' of said connecting` circuit With said called line and the actuation of onev of said keys, ior disassociating said ringing keys and said telephone set 'from said connecting circuit. v

17. In a telephone system, a calling sub scribers line, a called suloscrihers line, a cord circuit having answering and calling ends for interconnecting said lines, a sleeve relay in said cord circuit operated in response to the connection of the answering end of said cord circuit With said calling subscribers line, a supervisory relay associated With said cord circuit and operatively connected therein in response tothe operation of said sleeve relay, and a holding circuit forl said sleeve relay including operated contacts of said supervisory relay completed in response to the connection `of the calling end ci said cord circuit with said called line and broken to disconnect said supervisory relay from its operative connection in said cord circuit in response to re-l placement of the calling subscribers receiver on the svvitchhook.

18. In a telephone system,'a calling telephone line, an operators link circuit having a manual connection terminal for connecting With said line, an operators telephone set, means for connecting said Vset to said link circuit, a sleeve relay controlled over the connected line for controlling said means for connecting said set to said link circuit and for operatively disassociating the sta tion of said line from said link, and a l1old ing circuit for said relay including a contact of said manual connection terminal.

19. In a telephone system, a calling telephone line, on operators link circuit hav` ing a manual connection terminal for connecting with said line, a supervisory relay in said link circuit, a signal controlledv thereby, a sleeve relay controlled over the connected line for operatively disassociat-` ing the station of said line 'from said link and a locking circuit for said sleeve relay including a contact of said supervisory relay.

In Witness whereof, I hereunto subscribe my name this 27 th day of November A. D., 1923.

CLARENCE B. FOWLER. 

